Test disk performance

Last update: April 16 2025

Test disk performance

Linux

For complete testing of cloud server disk performance (read and write IOPS and throughput), use the utility fio. For testing you can use file tests — prepared text files with test settings.

1. Install the fio utility.

2. Prepare the disk for testing.

3. Test performance.

Test results can be compared to network disk limits and local disks.

1. Install the fio utility⁠

1. Connect to the server.

2. Install the utility fio:

   sudo apt update
   sudo apt install fio

2. Prepare the disk for testing⁠

carefully

Do not use a disk that contains any information for testing — all data on the disk will be destroyed in preparation for testing.

You can use a separate file on the disk for tests, but the result may not be representative, especially if you are using a root partition.

To exclude the influence of services and file system performance on the test result, we recommend the following create an empty network drive and fill it with data.

1. Create a blank disk.

2. Connect the disk to the cloud server.

3. Look at the name of the blank disk:

   lsblk

   A list of cloud server disks will appear in the response. Copy the name of an empty disk.

4. Fill the empty disk with data:

   dd if=/dev/urandom of=/dev/<sdX> bs=4M

   Specify <sdX> — name of the blank disk that you copied in step 3.

3. Test performance⁠

Can be used for:

• IOPS testing — random write or read in 4KB blocks;
• capacity testing — random write or read in 4 MB blocks.

Test IOPS⁠

Recording

1. Open the CLI.

2. Create a test file in a text editor nano:

   nano write.ini

3. Add content to the test file:

   [writetest]
   size=2000M
   blocksize=4k
   filename=/dev/sdb
   rw=randwrite
   direct=1
   buffered=0
   ioengine=libaio
   iodepth=32

   Here:

   • size — total file size for testing;
   • blocksize — size of one block of data for testing;
   • filename — path to the file to be used for testing. The example above shows a test with writing to disk with the parameter filename=/dev/sdb;
   • iodepth — number of streams.

4. Exit the text editor nano while saving changes: press Ctrl+Xand then Y+Enter.

5. Run the test:

   fio write.ini

   In the output of the test, look at the IOPS value. Example output:

   write: IOPS=118, BW=475KiB/s (487kB/s)(2000MiB/4310296msec); 0 zone resets

Reading

1. Open the CLI.

2. Create a test file in a text editor nano:

   nano read.ini

3. Add content to the test file:

   [readtest]
   size=2000M
   blocksize=4k
   filename=/dev/sdb
   rw=randread
   direct=1
   buffered=0
   ioengine=libaio
   iodepth=32

   Here:

   • size — total file size for testing;
   • blocksize — size of one block of data for testing;
   • filename — path to the file to be used for testing. The example above shows a test with writing to disk with the parameter filename=/dev/sdb;
   • iodepth — number of streams.

4. Exit the text editor nano while saving changes: press Ctrl+Xand then Y+Enter.

5. Run the test:

   fio read.ini

   In the output of the test, look at the IOPS value. Example output:

   read: IOPS=320, BW=1280KiB/s (1311kB/s)(2000MiB/1599899msec)

Test throughput⁠

Recording

1. Open the CLI.

2. Create a test file in a text editor nano:

   nano write.ini

3. Add content to the file:

   [writetest]
   size=2000M
   blocksize=4M
   filename=/dev/sdb
   rw=randwrite
   direct=1
   buffered=0
   ioengine=libaio
   iodepth=32

   Here:

   • size — total size of the test file;
   • blocksize — the size of one block with which a read or write operation is performed;
   • filename — file to write or read. The examples below show tests with writing to disk with the parameter filename=/dev/sdb — write will also destroy the data and file system on the disk, if any;
   • iodepth — number of streams.

4. Exit the text editor nano while saving changes: press Ctrl+Xand then Y+Enter.

5. Run the test:

   fio write.ini

   In the test output, look at the throughput (BW) value. Example output:

   write: IOPS=25, BW=100MiB/s (105MB/s)(2000MiB/19974msec); 0 zone resets

Reading

1. Open the CLI.

2. Create a test file in a text editor nano:

   nano read.ini

3. Add content to the file:

   [readtest]
   size=2000M
   blocksize=4M
   filename=/dev/sdb
   rw=randread
   direct=1
   buffered=0
   ioengine=libaio
   iodepth=32

   Here:

   • size — total size of the test file;
   • blocksize — the size of one block with which a read or write operation is performed;
   • filename — file to write or read. The examples below show tests with writing to disk with the parameter filename=/dev/sdb — write will also destroy the data and file system on the disk, if any;
   • iodepth — number of streams.

4. Exit the text editor nano while saving changes: press Ctrl+Xand then Y+Enter.

5. Run the test:

   fio read.ini

   In the test output, look at the throughput (BW) value. Example output:

   read: IOPS=25, BW=100MiB/s (105MB/s)(2000MiB/19911msec)

Windows

To fully test cloud server disk performance (read/write IOPS and throughput), use the CrystalDiskMark utility. We recommend testing on an additional cloud server disk.

1. Install the CrystalDiskMark utility.

2. Test performance.

Test results can be compared to network disk limits and local disks.

1. Install the CrystalDiskMark utility⁠

1. Download CrystalDiskMark.

2. Run the installer.

3. Follow the steps to install the utility.

2. Test performance⁠

Before testing, terminate third-party application processes or reboot to Safe Mode. We recommend testing on an additional disk.

Can be used for:

• IOPS testing — random write and read in 4KB blocks;
• capacity testing — random write and read in 4 MB blocks.

Test IOPS⁠

1. Run CrystalDiskMark.

2. Go to Profile.

3. Select Demo.

4. Go to Settings → Settings.

5. In the block Profile:Demo:

   5.1 In column Type select the test type — RND. This test type is responsible for random reading and writing.

   5.2 In the column Block Size select the block size for testing — 4KiB.

   5.3 In the column Queues select the depth of the request queue for testing — 32.

   5.4 In the column Threads select the number of download threads — 1.

6. Click OK.

7. In units of measure, select IOPS.

8. Click ALL. Disk IOPS testing will start.

9. In the test output, look at the read and write IOPS value. Example output:

   Read 325 IOPS
   Write 121 IOPS

Test throughput⁠

1. Run CrystalDiskMark.

2. Go to Profile.

3. Select Demo.

4. Go to Settings → Settings.

5. In the block Profile:Demo:

   5.1 In column Type select the test type — RND. This test type is responsible for random reading and writing.

   5.2 In the column Block Size select the block size for testing — 4MiB.

   5.3 In the column Queues select the depth of the request queue for testing — 32.

   5.4 In the column Threads select the number of download threads — 1.

6. Click OK.

7. In units of measure, select MB/s.

8. Click ALL. The disk throughput test will start.

9. In the test output, see the read and write throughput value. Example output:

   Read 106.5 MB/s
   Write 95.6 MB/s